Insulating metal lath



Oct. 20, 1931. D. B. ARNOLD 1,828,351

INSULATING METAL LATH Filed Aug. 22, 1928 [nae/2201':

Patented Oct. 20, 1931 P TEN OFFICE:

DAVID: B. ARNOLDK 01+ ,nnooirnrnn, MillssAoHUsnrrs, AssI NoB, BY MEsnn gassrem Minutes, To. EAsTnnnL EXPANDED-METAL.coMrAnY,or CAMBRIDGE, MASSACHU- sE'r'rsA CORPORATION on MAssAoHUsETrs Y METAL ATH ja 'gii u fn filedfaugu st 2251928. Serial No. 301,192,

inventionhasforits object a metal lath covered on one side with fibrous nas's having heat and sound insulating "qualities, the whole being intended to afford a backing and support for plaster, as well as a'n'insulation for the building. I f

Heretofore it has been proposed to employ fibrous material of various kinds as a backing forplaster to reduce the'transmission 'of heat and 'consequently'to make thehouse wh'ie it is used warmer." It has also been proposed to covercert'ain portions of metal lath with fibrous material to prevent the plaster being pushed through themeshes' of the expanded metal and falling down inside and thus being wasted.

My present invention provides a combined metal lath and light porous insulating-blanket which serves also as a" plaster by reducing the amount of plaster 'requlred.

Nevertheless, the material provided in' lny' present invention, afiords a perfect bond between the plaster and the metal, lath lwith the expenditure of minimum amount, of

I plaster. My invention also includes a"meth 0d of mannfacturingthe material to-produce a light porous material, having heat and sound insulating qualities in ahigh degree.

In the preferred form of my invention I also construct the material spam the edges of the metal lath vo'f adjacent-sheetsoverlap, and where possible the edgeribs areinterlocked, if ribbed lath is used; while .thejedges of the fibrous blanket butt againsteach other 3 sothat a smooth even surface of the insulating blanket results andby the overlapping of the lath additional strength and stiffness is given to the plastered wall.

Referring now to the drawings:

Fig. 1 is a longitudinal section of the essential elements of a machine illustrating the method of manufacturing the material embodying my invention.

Fig. 2 is a fragmentary plan View of the machine shown in Fig. 1.

Fig. 3 is a transverse section on a larger scale of a piece of material embodying my invention. 7

Fig. 4 is a plan View of the material show in Fig. 3.

f 5 is a detail showing the construction at the edgeofthe sheet and the plaster coat, aswell as the manner in which the ribbed edges'of the sheets are overlapped to produce abutt joint of the insulating material and a smooth surface on the insulating backing. Fig. 6 is a detail showing one of the groove forming members employed in practicing the method of manufacturing the material which is described herein. I

i The general construction of the finished material will best be understood by referring to Figs. 3 and 4. At A is shown a portion of a sheet of metal lath which may be of any well known construction, but is preferably of the ribbed type having longitudinal ribs 11, 11. These ribs are connected by a reticulatedporeon conveniently formed by" slitting and expanding metal in a wellknown manner. In 4 the form shown in the drawings there are intermediate ribs 12,12connectejdby strands I3, the whole forming what is known in the trade as rib lath, of one well known pattern. In the form shown in the drawingsthe strands lSfareinclined to theplane of the sheet as shown particularly in Fig. 3. This type of expanded metal lath is advantageous 1n connection with the manufacture of the 7 material embodying my invention because it has the necessary rigidity, this being 'afi forded by the U-shapedribs l1 and the mesh surface is of such a character that the fibrous material with which it isbacked readily and strongly adheres toit. The metal lath A of whatever kind is chosen is covered on one side by a thick coating or blanket'of fibrous'material which is preferably made of a dry paper fibre pulp whichmay ormay'not be treated with water proofing, fire proofing or adhesive I find in practice thatexcell'ent shown in Fig. 6'. Y These groove-forming members are preferably of the shape shown being slightly tapering. Their spacing side- Wise on the sheet is determined somewhat by the character of the metal lath employed and somewhat by the use to which the finished product is to be'put. In practice I find it sirable to space them somewhat uniforml across the sheet. As the sheet of metal lat A travels through the machine, one or more heavy layers of paper pulp mixed with-or suspended in water are deposited on the metal lath and on the groove forming members 14. The water is removed or extracted from the pulp in such a way as to leave the fibres loose and the material light and porous, so that the heat insulating qualities are not diminished. This is preferably done by means of suction which extracts the water without compressing the fibres. In the drawings, .1 have shown a suction box S for this purpose. The layer of pulp which is designated 13 is thickenough to make a thick layer 0 ofthe dry .fibre .in the finished material so as to give to the finished material the necessary heat insulating qualities. The layer of fibrous material coversover the groove forming members 14 and over the exposed parts of the remainder of the sheet of metal lath except on two edges .as will be explained hereafter. The fibres mat together around the strands of the metal lath and to each other sufficiently so that the insulating blanket is .well tied to the strands of the metal lath. The under surface of the sheet is left in a rough condition with portions of the strands of the expanded metal exposed and other por .tions embedded or partly embedded in the fibrous .material. The groove forming mean bers 1.4 are then withdrawn lengthwise from the position shown in Figs. 1 and 2, thisbeing facilitated by the tapering shape of the groove formin members. This leaves, what are con-- venient ly termed closed or confined grooves,

between the metal lath and the fibrous ma-- terial.

In practice and where rib lath "is-employed I leave one longitudinal and one transverse edgeof the sheet bars as shown at 15 and 1.6

in Fig. .2 and cover the other two edges 17 and .18 in that figure. This makes it possible to overlap the ,rib on one sheet with .the rib von the neXt sheet as shown at 3170 in Fig.

tinuous surface on the blanket side .of sheet.

The material is fastened in place on th studding aOI furring in .the ordinary way and p laster'is applied in the ordinary unanner. .Over those portions of "the material where .there are no confined grooves, .orpver .the whole surface, if grooves are not ,exn-

.fibrous pulp and fini h ng ployed, the plaster penetrates the small interstices and depressions in the exposed portions of the fibrous material and the spaces about the exposed parts of the strands and forms bonds which are g erally suffi ient to h the plaster .in place but whe the ico fi grooves are employed a much better bond is produced. In this case the plaster enters the confined grooves "'21, Q0 pusingthrou h and beyond the strands .of metal la and reunites in the The plaster iii the grooves forms plaster ribs which give added strength and stiffness to the wall. As the grooves are closed the plaster cannot run through and drop own behind the wall, nor

can more plaster pass the metal lath han is me tal lath.

2. The process at making building material whichcon prises .form ngonone sid f a sheet of metal 'lat'h a layer of semi-liquid fibrous. ulp.,.f.orming spa es between the-fibronspui p an's'iilath, and extracti ate from the 13111 "by mea s wh ehleaves he resulting layer ogdry fibre 'iua li ht po ous cond tion- The p ocess lei .mai g b i d ng ,mat rial which omprises ,Iermi'i gon one side f a sheet 0f, .I. l.t.&. l13- a laye of m -liqu d h the layer by exracting from the .pul t e ater containe therein by suction so that the resulting layer .wiH-be'iu a iighnporous condition.

'4. "The process of making building material whicl-r-comprises forming .on one side of a sheet .ofjnietal'lath alightporous layer of fibres by depositingtheiion a semi-liquid ,fi-

brous pulp and finishing the-layer by drying the pulp while {he fibres are in their loose (1e osigte'd condition.

testi-monywhereof I afiix my signature.

"DAVID "B. ARNOLD 

